What does the direction of thumb indicate in the right-hand thumb rule? In what way this is different from Fleming’s Left-Hand Rule?
Right Hand Thumb Rule: The direction of magnetic field in relation to direction
of electric current through a straight conductor can be depicted by using the Right Hand Thumb Rule. If a current carrying conductor is held by right hand, keeping the thumb straight and if the direction of electric current is in the direction of thumb, then the direction of wrapping of other fingers will show the direction of magnetic field.
Therefore, as per right hand thumb rule, the thumb shows the direction of electric current.
On the other hand, Fleming’s Left-Hand-Rule explains effect of magnetic field on a current
Fleming’s Left Hand Rule: If direction of electric current is perpendicular to the magnetic field, the direction of force is also perpendicular to both of them. The Fleming’s Left Hand Rule states that if the left hand is stretched in a way that the index finger, the middle finger of stretched left hand show the direction of magnetic field and direction of electric current respectively and the thumb shows the direction of motion or force acting on the conductor a.